Method of making balls



June 10, 1941.

w. T. BROWN 2,245,324

METHOD OF MAKING BALLS Filed Aug. 25, 1938 BY wag ATTORNEY Patented June 10, 1941 2,245,324

UNITED STATES PATENT OFFICE METHOD OF MAKING BALLS William T. Brown, Short Hills, N. J., assignor to A. G. Spalding & Bros. Inc., New York, N. Y., a corporation of Delaware Application August 25, 1938, Serial No. 226,733

' 11 Claims. (Cl. 154-16) This invention relates to methods of making as with melton. Steps other than the preworkballs. More particularly, the inventionrelates ing to which the ball is subjected are convento a factory preworked or wom-in ball such tiona, as are the machines used in the manuas used in tennis, hand ball or squash. facture. However, according to the present in- There is a strong preference among players, in vention the balls are made somewhat harder than tennis, squash-racket, hand ball and various desired for initial use, as by increased pressure sports using balls, and particularly those balls of inflation within the ball and/or by increased filled with gas under either light or considerable hardness in the body material of the ball, the pressure, for a ball that is lively and does not preworking being then continued until the hardchange appreciably during use for a reasonable ness or compressibility becomes that specified in time. Heretofore it has not been possible to the regulations for new balls for the various meet this requirement. In tennis, for example, sports. During play these preworked balls which the official regulations prescribe the properties were initially harder than standard or regular of the ball, including initial compressibility. balls remain at the predetelmined standards for During use, a ball made to meet these requirea much longer time than regular balls do. ments soon becomes somewhat soft or too com- The improved balls of the present invention pressible. For this reason, it is not uncommon are made by subjecting the harder than standin championship play for players to demand a ard balls to a kneading action, which in its dozen or more balls for use in a single match. simplest form is accomplished by rolling balls It is an object of this invention to provide an 10 between plate members II and I2 of the maimproved ball of the kind described that inchine shown in Fig. 1 as by rotating plate il creases in compressibility during use at a. lower and/or I 2 by means described hereinafter.

rate than balls heretofore made for a given sport. To subject the balls to a more rigorous work- Further objects and advantages of the invening the plate members II and I2 are alternatee tion will be apparent as it is better understood ly moved towards and away from each other, so by reference to the following specification and as to cause repeated alternate compression and accompanying drawing, in which re-expansion of the balls. Suitably the plates Figs. 1 and 2 are side elevations, partly in secare moved so far apart, in .the one stage of the tion, of machines for use in making the improved oscillation, that the ball reassumes approximateball. Both of these figures are, in part, diagram- 1y it original shape, under the influence only of matic. the prevailing atmospheric pressure.

In general, I have found that a ball made in The compression, with each movement of the the usual manner and then subjected to working, plates toward each other, compresses the ball to that is, alternate compression and re-expansion, a predetermined extent that can be controlled undergoes at first a relatively rapid change in by the setting of the machine. hardness (as measured by compressibility) and The machine may be provided with a. lifter l3, then approaches the condition in which further activated by a chain or belt I41, passing around working causes only a slight change. an eccentrically mounted pulley (not shown).

The invention comprises conditioning a ball The compressing force is the weight of the mechby preworking in order to bring it to a more or 40 anism which includes the upper plate H, the less stabilized condition as to hardness before shaft i 5, and weights l6 mounted thereupon. the ball is used in play. To produce more sudden blows, there may be This preworking may be effected, for instance, used the eccentrically mounted disc I! rotated inmachines 0f the t pe shown, although it will as by means of belt l8, and provided with upbe understood that the invention is not limited standing knob or projection l9, which for each to any particular device for efiecting the working rotation of the disc I'l, bumps against and lifts of the ball. I the rounded knob 20, thus forcing suddenly It will be understood that the first steps in the upward the lower plate l2. making of the improved ball of the present in- Suitably, the plate I2 is provided with upstandvention include the formation of a sphere of 5 ing peripheral rim 2!, which prevents the balls resilient, rubbery material, such as rubber or being worked from rolling from the plate. Also, Neoprene. Balls for some sports are hollow and if desired, the plate l2 may be provided with an inflated with gas under light or considerable inner upstanding ring 22, so that the balls bepressure. In the case of .the tennisball, the resiling worked are confined in a circular race beient sphere is given a fibrous exterior coating, tween the elements 24 and Z2.

Preferably, the machine produces not only compression and re-expansion but also rolling of the balls. For this latter eflect, the plate H is given a lateral movement, say, rotation, by means of the pulley 23 and suitable driving mechanism therefor including belt 2,4. Also, although it may take slightly longer to effect the desired degree of working it is possible to subject the balls to the rolling action alone.

In the machine shown in Fig. 2, there are used again. with the balls It, the lifter l3, and upper and lower plate members H and 12. However.

the upper plate is eccentrically mounted, so the. there is oscillation of the plate not only up and down but also laterally while, at the same time, the plate is being rotated. Also, the up-anddown movement may be eliminated and just the rotatory or eccentric rotatory movement used alone.

In such machines tennis, squash racket, hand balls, or the like are subjected to the application of a compressive force, in turn, to various parts of the exterior surface of the balls, alternated with substantially complete release of the pressure between each application thereof.

With such conditioning, the balls come to have a minimized rate of change of hardness with further working or with use in play. For instance, I have found that a tennis ball subjected to repeated hitting against a hard surface for 25 minutes shows only approximately one-fifth as rapid a change in compressibility during the last ten minutes of this period as during the first fifteen minutes. Other tests confirm these results and show that the rate of change of compressibility of the ball decreases as the ball is manipulated. (compressibility of a tennis ball or the like may be determined by the use of the machine described in British Patent No. 230,250, to Stevens.)

Depending in part upon the rate of oscillation of the compressing members, the time of working in machines of the kind illustrated may be varied, say. between 2 and 10 minutes. In any case, the degree to which the ball is compressed at any time is moderate but substantial, as, for example, slightly greater than caused by striking the ball in play.

The duration of and the extent of the preworking "will also vary somewhat with different balls. For any given ball, the working is continued for a substantial period of time, that is, until there is a minimized change in compressibility with further working, as for example, a change of compressibility per minute that is not more than a third of the change for the first minute of working.

It will be appreciated that the lower plate member 12 may also be rotated. When this is desired, it is preferably rotated in a direction opposite to the rotation of the plate member II by a belt 30 connected to pulley 3| and 32, the latter through shafts 33 and 34 and the gear mechanisms 35 and 36 being connected to the electric motor 31. When it is desired to omit rotation of either the plate member II or l2, the belts 24 or 30 respectively are disconnected. Likewise, when it is desired to forego the impact action achieved with the lug l9 it is merely necessary to disconnect the belt iii.

The details given are for the purpose of illustration, not restriction, and variations within the spirit of the invention are intended to be included within the scope of the appended claims.

I claim:

1. In making and conditioning a resilient ball, the method which comprises making a ball harder than playing standard, and then rolling the ball under pressure until it meets playing standard.

2. In the mass production manufacture of gas-inflated balls, the process which comprises forming a hollow sphere of resilient rubbery material, inflating the sphere with gas under pressure to produce a ball less compressible than playing standard, compressing said ball to a predetermined substantial extent, and then allowing the ball to re-expand under atmospheric pressure, the compression and re-expansion being repeated in alternation, and the repetition thereof being continued until the ball meets playing standard.

3. In making a ball. the method which comprises forming a hollow sphere of resilient rubbery material and harder than playing standard, inflating the sphere with gas under pressure; and kneading the said sphere until it is within playing standard.

4. In the mass production manufacture of gasinflated balls, the method which comprises forming a hollow sphere of resilient rubbery material, inflating the ball with gas under pressure, said forming and inflating providing a ball harder than standard, and repeatedly applying a rapidly intermittent compressing force, consisting of pressure applied in turn to various portions of the exterior of the sphere altern'ating with substantially complete release of pressure after each application thereof, said applications of pressure being applied substantially as soon as said ball has returned to substantially normal shape after said releases, said intermittent compressing force being applied until the ball meets playing standard.

5. In making a ball, the method which comprises forming a hollow sphere of resilient rubbery material and inflating the sphere with gas under pressure until it is harder than playing standard, and subjecting the sphere to compression and rolling until it is within playing standard.

6. In making a ball, the method which comprises forming a hollow sphere of resilient rubbery material harder than playing standard, and flexing the inflated sphere until further flexing for a substantial period of time produces a minimum of change in compressibility.

'7. In the mass production'manufacture of gasinflated balls, the method which comprises forming a hollow sphere of resilient rubber material, inflating the sphere with gas to produce a ball less compressible than playing standard, and repeatedly subjecting the said sphere to a multiplicity of compressive blows of intensity at least approximately equal to those to which the ball will be subjected during use until the compressibility of the ball is increased to playing standard.

8. In making a play ball fllled with compressed gas, the method which comprises'making the ball of hardness substantially greater than desired for the initial use of the ball and then repeatedly compressing and reexpanding the ball until the hardness is reduced to that desired for initial use.

9. In making a play ball filled with compressed gas, the method which comprises making the ball of hardness substantially greater than desired for the initial use of the ball and then repeatedly compressing and reexpanding and rolling the ball until the hardness is reduced to that desired for initial use.

10. In making a play ball, the method which comprises making the ball of a hardness greater than that desired for playing use thereof, and rolling the ball until the hardness thereof is reduced to that desired for playing use.

11. In the mass production manufacture of balls, the method which consists in the steps of forming a hollow sphere of resilient material, 10

WILLIAM T. BROWN. 

